Cervical Coupling Motion Characteristics in Healthy People Using a Wireless Inertial Measurement Unit

Figure 3

Amount of motion as area under curve. The amount of rotation is defined as the area under curve from the initial point to the maximum rotation point. This area was used to calculate the average angle of coupling motion. Positive values represent flexion, right side bending, and right axial rotation. In this case, there is little coupling motion in flexion.